/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.accumulo.test.constraints;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import org.apache.accumulo.core.data.ColumnUpdate;
import org.apache.accumulo.core.data.Mutation;
import org.apache.accumulo.core.data.constraints.Constraint;

/**
 * This class is an accumulo constraint that ensures values are numeric strings.
 */
public class NumericValueConstraint implements Constraint {

  static final short NON_NUMERIC_VALUE = 1;
  static final String VIOLATION_MESSAGE = "Value is not numeric";

  private static final List<Short> VIOLATION_LIST =
      Collections.unmodifiableList(Arrays.asList(NON_NUMERIC_VALUE));

  private boolean isNumeric(byte[] bytes) {
    for (byte b : bytes) {
      boolean ok = (b >= '0' && b <= '9');
      if (!ok)
        return false;
    }

    return true;
  }

  @Override
  public List<Short> check(Environment env, Mutation mutation) {
    Collection<ColumnUpdate> updates = mutation.getUpdates();

    for (ColumnUpdate columnUpdate : updates) {
      if (!isNumeric(columnUpdate.getValue()))
        return VIOLATION_LIST;
    }

    return null;
  }

  @Override
  public String getViolationDescription(short violationCode) {

    switch (violationCode) {
      case NON_NUMERIC_VALUE:
        return "Value is not numeric";
    }

    return null;
  }

}
